This paper discusses the numerical prediction of the induced pressure and lift of the planing surfaces in a steady motion based on the potential flow solver as well as the spray drag by use of the practical method. The numerical method for computation of the induced pressure and lift is potential-based boundary element method. Special technique is identified to present upwash geometry and to determine the spray drag. Numerical results of a planing flat plate and planing craft model 4666 are presented. It is shown that the method is robust and efficient and the results agree well with the experimental measurements with various Froude numbers. This paper discusses the numerical prediction of the induced pressure and lift of the planing surfaces in a steady motion based on the potential flow solver as well as the spray drag by use of the practical method. The numerical method for computation of the induced pressure and lift is a potential-based boundary element method. Special techniques are identified to present upwash geometry and to determine the spray drag. Numerical results of a planing flat plate and planing craft model 4666 are presented. It is shown that the method is robust and efficient and the results agree well with the experimental measurements with various Froude numbers